The invention relates to chemically fuelled laser and to a method for increasing the efficiency of such lasers. More specifically, the invention relates to lasers having a combustion chamber and a diffuser which are both cooled in a regenerative manner.
It is conventional to increase the efficiency of rockets with the aid of a regenerative cooling. In this type of cooling the fuel substances are conducted as a coolant through the wall of the combustion chamber. In this manner the heat produced by the combusted gas and supplied to the walls of the combustion chamber is not lost. Rather, the heat is again supplied to the combustion chamber due to the resulting heating of the fuel materials.
In chemical lasers the laser medium is also produced by a combustion, for example, in a gas dynamic CO.sub.2 laser or in a chemical fluorine hydrogen laser. It is known in connection with such lasers to cool the combustion chamber thereof in the above mentioned regenerative manner.
Generally, chemically fuelled lasers are characterized in that the laser gas is cooled by expansion through Laval nozzles whereby a small proportion of the chemically supplied heat is delivered as laser power. Thereafter the laser gas flows through a diffuser where it is compressed substantially to atmospheric pressure whereupon it exits into the atmosphere or into a container. During this diffusion and compression the gas achieves a temperature in the diffuser which approximates that of the gas combustion chamber.